I will work on this feature, but I will need your help first my dear artists! 
@dkazakov @freyalupen and @tiar completed the enormous work of rewriting Paint Engine’s Settings code to Lager lib.
This rewrite will make it much easier to do UX work like the one in this topic.
We need you to test if new code works like it used to, so we can merge it as soon as possible. Sooner it will be tested, sooner it will be merged, and sooner I will start working on shortcuts and gizmos to control brush rotation (and maybe even mirroring).
Test builds, and KA topic is here: [needs testing] First testing packages for the lager-based brush editor - #33 by dkazakov